Umbilical venous blood gas analysis for neonatal assessment

Abstract

Umbilical venous pH is claimed to mirror fetal acid-base status. Importantly, it is easier to perform. The aim of this study is to : 1. Evaluate the umbilical venous blood gas (UVBG) profile of normal newborns and to compare UVBG in the following situations: presence or absence of asphyxia presence or absence of meconium-stained amniotic fluid presence or absence of respiratory distress: and in newborns that did and did not survive and 2. To study the peripheral venous blood gas (PVBG) profile of newborns that develop cardio-respiratory insufficiency (CRI). Venous blood gas (VBG) was performed in 961 newborns consecutively admitted to the neonatal nursery over one year and in 100 controls. PVBG was also performed in 370 admissions to the nursery that developed signs of CRI. Demographic, clinical and outcome data were collected. Mean UVBG parameters (pH, pCO₂, HCO₃, base deficit, pO₂ and SO₂%) were compared between different groups of newborns using t test. This study had ethical approval. Of the 3349 live births over one year, 961 (28.7%) needed intensive care. Of these, 123 (12.8%) died. All the mean cord gas parameters differed significantly between who died and who survived. Metabolic acidosis and hypoxemia were conspicuous on PVBG among babies with CRI. Except for PO₂ all the mean parameters of UVBG differed significantly with asphyxia and meconium-stained amniotic fluid. When similar comparison was made among newborns that did or that did not develop respiratory distress, the difference was significant for all the parameters except SO₂%. UVBG gives useful information about common neonatal morbidities and appears to be a useful tool for neonatal assessment. PVBG gives objective information about babies with CRI that may need special interventions.

Keywords

Neonatal assessment - cord blood gases - perinatal asphyxia - fetal distress - birth asphyxia - respiratory distress - meconium staining